| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mnuprdlem1.1 | ⊢ 𝐹  =  { { ∅ ,  { 𝐴 } } ,  { { ∅ } ,  { 𝐵 } } } | 
						
							| 2 |  | mnuprdlem1.3 | ⊢ ( 𝜑  →  𝐴  ∈  𝑈 ) | 
						
							| 3 |  | mnuprdlem1.4 | ⊢ ( 𝜑  →  𝐵  ∈  𝑈 ) | 
						
							| 4 |  | mnuprdlem1.8 | ⊢ ( 𝜑  →  ∀ 𝑖  ∈  { ∅ ,  { ∅ } } ∃ 𝑢  ∈  𝐹 ( 𝑖  ∈  𝑢  ∧  ∪  𝑢  ⊆  𝑤 ) ) | 
						
							| 5 |  | eleq1 | ⊢ ( 𝑖  =  ∅  →  ( 𝑖  ∈  𝑢  ↔  ∅  ∈  𝑢 ) ) | 
						
							| 6 | 5 | anbi1d | ⊢ ( 𝑖  =  ∅  →  ( ( 𝑖  ∈  𝑢  ∧  ∪  𝑢  ⊆  𝑤 )  ↔  ( ∅  ∈  𝑢  ∧  ∪  𝑢  ⊆  𝑤 ) ) ) | 
						
							| 7 | 6 | rexbidv | ⊢ ( 𝑖  =  ∅  →  ( ∃ 𝑢  ∈  𝐹 ( 𝑖  ∈  𝑢  ∧  ∪  𝑢  ⊆  𝑤 )  ↔  ∃ 𝑢  ∈  𝐹 ( ∅  ∈  𝑢  ∧  ∪  𝑢  ⊆  𝑤 ) ) ) | 
						
							| 8 |  | 0ex | ⊢ ∅  ∈  V | 
						
							| 9 | 8 | prid1 | ⊢ ∅  ∈  { ∅ ,  { ∅ } } | 
						
							| 10 | 9 | a1i | ⊢ ( 𝜑  →  ∅  ∈  { ∅ ,  { ∅ } } ) | 
						
							| 11 | 7 4 10 | rspcdva | ⊢ ( 𝜑  →  ∃ 𝑢  ∈  𝐹 ( ∅  ∈  𝑢  ∧  ∪  𝑢  ⊆  𝑤 ) ) | 
						
							| 12 | 2 | adantr | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐹  ∧  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) ) )  →  𝐴  ∈  𝑈 ) | 
						
							| 13 |  | simprl | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐹  ∧  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) ) )  →  𝑎  ∈  𝐹 ) | 
						
							| 14 |  | simpr | ⊢ ( ( 𝜑  ∧  ∅  ∈  𝑎 )  →  ∅  ∈  𝑎 ) | 
						
							| 15 |  | 0nep0 | ⊢ ∅  ≠  { ∅ } | 
						
							| 16 | 15 | a1i | ⊢ ( 𝜑  →  ∅  ≠  { ∅ } ) | 
						
							| 17 | 3 | snn0d | ⊢ ( 𝜑  →  { 𝐵 }  ≠  ∅ ) | 
						
							| 18 | 17 | necomd | ⊢ ( 𝜑  →  ∅  ≠  { 𝐵 } ) | 
						
							| 19 | 16 18 | nelprd | ⊢ ( 𝜑  →  ¬  ∅  ∈  { { ∅ } ,  { 𝐵 } } ) | 
						
							| 20 | 19 | adantr | ⊢ ( ( 𝜑  ∧  ∅  ∈  𝑎 )  →  ¬  ∅  ∈  { { ∅ } ,  { 𝐵 } } ) | 
						
							| 21 | 14 20 | elnelneqd | ⊢ ( ( 𝜑  ∧  ∅  ∈  𝑎 )  →  ¬  𝑎  =  { { ∅ } ,  { 𝐵 } } ) | 
						
							| 22 | 21 | adantrr | ⊢ ( ( 𝜑  ∧  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) )  →  ¬  𝑎  =  { { ∅ } ,  { 𝐵 } } ) | 
						
							| 23 | 22 | adantrl | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐹  ∧  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) ) )  →  ¬  𝑎  =  { { ∅ } ,  { 𝐵 } } ) | 
						
							| 24 |  | elpri | ⊢ ( 𝑎  ∈  { { ∅ ,  { 𝐴 } } ,  { { ∅ } ,  { 𝐵 } } }  →  ( 𝑎  =  { ∅ ,  { 𝐴 } }  ∨  𝑎  =  { { ∅ } ,  { 𝐵 } } ) ) | 
						
							| 25 | 24 1 | eleq2s | ⊢ ( 𝑎  ∈  𝐹  →  ( 𝑎  =  { ∅ ,  { 𝐴 } }  ∨  𝑎  =  { { ∅ } ,  { 𝐵 } } ) ) | 
						
							| 26 | 25 | orcomd | ⊢ ( 𝑎  ∈  𝐹  →  ( 𝑎  =  { { ∅ } ,  { 𝐵 } }  ∨  𝑎  =  { ∅ ,  { 𝐴 } } ) ) | 
						
							| 27 | 26 | ord | ⊢ ( 𝑎  ∈  𝐹  →  ( ¬  𝑎  =  { { ∅ } ,  { 𝐵 } }  →  𝑎  =  { ∅ ,  { 𝐴 } } ) ) | 
						
							| 28 | 13 23 27 | sylc | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐹  ∧  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) ) )  →  𝑎  =  { ∅ ,  { 𝐴 } } ) | 
						
							| 29 | 28 | unieqd | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐹  ∧  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) ) )  →  ∪  𝑎  =  ∪  { ∅ ,  { 𝐴 } } ) | 
						
							| 30 |  | snex | ⊢ { 𝐴 }  ∈  V | 
						
							| 31 | 8 30 | unipr | ⊢ ∪  { ∅ ,  { 𝐴 } }  =  ( ∅  ∪  { 𝐴 } ) | 
						
							| 32 |  | uncom | ⊢ ( ∅  ∪  { 𝐴 } )  =  ( { 𝐴 }  ∪  ∅ ) | 
						
							| 33 |  | un0 | ⊢ ( { 𝐴 }  ∪  ∅ )  =  { 𝐴 } | 
						
							| 34 | 31 32 33 | 3eqtri | ⊢ ∪  { ∅ ,  { 𝐴 } }  =  { 𝐴 } | 
						
							| 35 | 29 34 | eqtrdi | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐹  ∧  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) ) )  →  ∪  𝑎  =  { 𝐴 } ) | 
						
							| 36 |  | simprrr | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐹  ∧  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) ) )  →  ∪  𝑎  ⊆  𝑤 ) | 
						
							| 37 | 35 36 | eqsstrrd | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐹  ∧  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) ) )  →  { 𝐴 }  ⊆  𝑤 ) | 
						
							| 38 |  | snssg | ⊢ ( 𝐴  ∈  𝑈  →  ( 𝐴  ∈  𝑤  ↔  { 𝐴 }  ⊆  𝑤 ) ) | 
						
							| 39 | 38 | biimprd | ⊢ ( 𝐴  ∈  𝑈  →  ( { 𝐴 }  ⊆  𝑤  →  𝐴  ∈  𝑤 ) ) | 
						
							| 40 | 12 37 39 | sylc | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝐹  ∧  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) ) )  →  𝐴  ∈  𝑤 ) | 
						
							| 41 |  | eleq2w | ⊢ ( 𝑢  =  𝑎  →  ( ∅  ∈  𝑢  ↔  ∅  ∈  𝑎 ) ) | 
						
							| 42 |  | unieq | ⊢ ( 𝑢  =  𝑎  →  ∪  𝑢  =  ∪  𝑎 ) | 
						
							| 43 | 42 | sseq1d | ⊢ ( 𝑢  =  𝑎  →  ( ∪  𝑢  ⊆  𝑤  ↔  ∪  𝑎  ⊆  𝑤 ) ) | 
						
							| 44 | 41 43 | anbi12d | ⊢ ( 𝑢  =  𝑎  →  ( ( ∅  ∈  𝑢  ∧  ∪  𝑢  ⊆  𝑤 )  ↔  ( ∅  ∈  𝑎  ∧  ∪  𝑎  ⊆  𝑤 ) ) ) | 
						
							| 45 | 11 40 44 | rexlimddvcbvw | ⊢ ( 𝜑  →  𝐴  ∈  𝑤 ) |